Clicking on this button will bring up an options
dialog for the selected plugin, allowing you to change various
aspects of it's behavior, or enable/disable certain of it's
features. Note that not all plugins have options to configure.

Enable/Disable

Clicking on this button will enable (checked box)
or disable (unchecked box) the selected plugin. This determines
whether or not the plugin will be loaded the next time you start
K-Meleon.